Conventional car headlights can only provide two working modes, namely, a low-beam mode and a high-beam mode. However, in some driving conditions, the conventional car headlights fail to provide suitable and sufficient road illumination. For example, when the car leans forward or backward due to a shifted center of gravity or bumping along a rough road, or when the car passes through a curved road, light beams from the headlights might not be able to fully project on and illuminate the road to thereby cause danger in driving. Therefore, there are increasing demands for adaptive headlights for car, which are also referred to as advanced car headlights.
According to the currently available adaptive headlight technique, a motor is used to drive the headlight to adjust its horizontal or sideward position. Either a headlight base or a reflection mirror is driven to achieve the positional adjustment of the headlight. However, the currently available car headlight beam adjusting technique has the disadvantages of slow response speed, high manufacturing cost, low flexibility in changing the headlight illuminating angles, etc.
In recent years, an adaptive car headlight technique using multiple light-emitting diodes (LEDs) as the light sources thereof has been developed. The multiple LED light sources are grouped and individually controlled to emit or not emit light beams, so as to show different headlight beam patterns.
However, the currently available high brightness LED technique is not mature, and the LED technique adopted by the existing adaptive headlight for car can be generally classified into two types. One of the two types applies the present LED light technique in the mass production of headlights and uses two or three groups of LED light sources for low beams, high beams and turning, respectively. The other type uses ultrahigh-brightness LED light sources as a design basis, and multiple LED light sources are arrayed at specific positions and angles. Different LED light sources are individually turned on or off under control according to actual need in different road conditions, so as to show required headlight beam patterns.
While the above-described adaptive car headlight using LED light sources has quick response time, high flexibility in headlight beam patterns and low maintenance cost, it has the disadvantage of non-continuous headlight beam pattern shifting, jumped headlight beam patterns, and causing discomfort to a rider's eyes.
It is therefore desirable and tried by the inventor to develop an improved road-adaptive vehicle headlight system, so that headlight devices on a car can quickly and flexibly produce different light beam patterns to increase the road visibility as well as the illumination areas of the headlight devices to ensure high safety in driving.